Comparison of water-retention functions obtained from the extended evaporation method and the standard methods sand/kaolin boxes and pressure plate extractor

Authors

  • Uwe Schindler,

    Corresponding author
    1. Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374 Müncheberg, Germany
    • Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374 Müncheberg, Germany
    Search for more papers by this author
  • Lothar Mueller,

    1. Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374 Müncheberg, Germany
    Search for more papers by this author
  • Milton da Veiga,

    1. Epagri – Experimental Station of Campos Novos, PO Box 116, 89620-000, Campos Novos (SC), Brazil
    Search for more papers by this author
  • Yuming Zhang,

    1. Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Sciences, 286 Huaizhong Rd., Shijiazhuang 050021, Hebei, China
    Search for more papers by this author
  • Sandro Schlindwein,

    1. Federal University of Santa Catarina, Department of Rural Engineering, CP 476, 88040-900 Florianópolis (SC), Brazil
    Search for more papers by this author
  • Chunsheng Hu

    1. Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Sciences, 286 Huaizhong Rd., Shijiazhuang 050021, Hebei, China
    Search for more papers by this author

Abstract

Knowledge of the soil hydraulic functions is required for various hydrological studies and for the simulation of water and solute fluxes in unsaturated soils. Sand/kaolin boxes are frequently used to determine these properties in the low-tension range. For higher tensions the pressure plate extractor is mainly applied. The extended evaporation method allows a more efficient determination of the water-retention curve in an adequate range. Besides this method enables to quantify simultaneously the unsaturated hydraulic-conductivity function. The objective of this study was to compare the water-retention curves obtained from the standard methods (STM) with those determined with the extended evaporation method (EEM). A set of 90 natural soil samples of different texture and origin was analyzed, and the agreement between the methods was statistically evaluated. The average water-content deviation (AWCD) of all samples was 1.83 vol.%, and the root mean square error (RMSE) 2.08 vol.%. The deviation of soil water-storage capacity in the pore-size classes 0–6, 6–30, 30–500, 500–1500 kPa varied between minimum –0.17 and 0.25 vol.% and maximum –2.89 and 2.36 vol.%, and confirmed the good comparability among the adopted methods. Systematic deviations between the methods were not found.

Ancillary